全自动凯氏定氮仪在测定干旱区土壤中全氮量的研究

本实验采用了UDK159全自动凯氏定氮仪对干旱区土壤全氮量的方法以及试验部分影响因素进行研究,结果表明：精密度试验中RSD在0.01919%～0.1073%之间(≤1%),用标准物质硫酸铵进行回收率检验,其回收率达99.5% 以上,检测准确度和精密度都符合国家标准的要求；在消化时间的选择上,变异系数为0.0088,表明土壤中有机物在30 min时已完全消化；而关于硫酸用量在10~15mL时为最佳值,干旱区土壤中氮一般含量为(0.260±0.003) %(P =0.95)。

Udk159 automatic Kjeldahl analyzer in the determination of dry soil nitrogen

This study uses a UDK159 automatic Kjeldahl apparatus arid soil total nitrogen methods as well as the uncertainty of test portion. The results showed that: precision tests RSD 0.01919% ~ 0.1073% in between, with a standard substance ammonium sulfate recovery test, the recovery rate of 99.5%, the detection accuracy and precision are in line with national standards; digestion time the choice of coefficient of variation was 0.0088, indicating that the organic matter in soil at 30 min was completely digested; while on the amount of sulfuric acid at10~15mL when the optimal value.